The present disclosure relates generally to the field of vehicles. The present disclosure more specifically relates to a sensor system in a steering wheel of a vehicle.
Current steering wheel sensor systems which detect hand placement on the steering wheel do not include a way to determine which way the wheel is being controlled (e.g., via a hold, grasp, touch, etc.). Such systems often utilize electric redistribution sensors, where an electric field is induced in a sensor electrode with an accurate voltage, current and frequency profile. Objects within proximity (such as human hands or body parts) tend to redistribute the electric field intensity and phase, resulting in the change of complex impedance as measured within the electric field circuit. The complex impedance can be a capacitance, an inductance, a resistance, or a combination thereof (e.g., a sensor that measures a capacitance component and an inductive component as I and Q components, respectively). What is needed is a system and method for determining when the steering wheel is being controlled through a grasp (e.g., when a hand palm skin surface engages the majority (or all) of the perimeter of the steering wheel rim or spokes).